鸡结膜结合淋巴组织的超微结构及其摄取抗原功能研究

SIUDIES ON THE ULTBASIRUCIURE AND FUNCTION OF ANTIGEN UPTAKE OF THE CONJUNCTIV A-ASSOCIATED LYMPHOID TISSUE(CALT)IN CHICKENS

１３２只２５日龄雏鸡的眼结膜结合淋巴组织（Ｃｏｎｊｕｎｃｔｉｖａ－ＡｓｓｏｃｉａｔｅｄＬｙｍｐｈｏｉｄＴｉｓｓｕｅ，ＣＡＬＴ），通过光镜、扫描电镜和透视电镜观察其组织细胞结构特征，使用不同示踪物（辣根过氧化物酶、碳和酵母菌）研究其摄取抗原功能．结果表明鸡ＣＡＬＴ主要位于下眼睑近侧端结膜穹窿处。扫描电镜下，覆盖淋巴组织表面的扁平上皮细胞呈多边形，表面积大，晶格状排列，微绒毛粗短而不规则，细胞之间连结紧密，偶见杯状细胞开日。透视电镜下，鸡ＣＡＬＴ上皮由浓染和淡染的两种扁平上皮细胞组成。浓染上皮细胞微绒毛多，胞浆多突，空泡丰富、胞核不规则。淡染上皮细胞微绒毛极少，表面多微褶，胞浆小有多量微丝，核圆形或椭圆形。上皮层内散见淋巴细胞。上皮基底膜下的淋巴组织中具有高内皮小静脉。手术封闭的结膜腔内注入示踪物试验证明，鸡ＣＡＬＴ具有摄取和传递抗原功能，示踪物均出现在ＣＡＬＴ内。辣根过氧化物酶可见于巨噬细胞和淋巴细胞中。研究结果表明：鸡ＣＡＬＴ是粘胶免疫系统的组成成分，是点眼免疫时抗原的摄取部位，在眼区粘膜免疫中起重要作用。

Ultrastructure and Function of Antigen uptake of Conjunctiva-Associated lymphoidtissue(CALT) in chickens of 25 day were studied by light、 electron microscop(Scap-ning and transTnission)and by using tracers(Horseradish peroxidase,carbon,saccharo-myces).The results showed that CALT was confined to the proxilnal part of the lowereyelid near the conjunctiva fornix.Under scanning electron microsco,the epithelialcells over lymphoid areas were flat and multilaleral,had short,thick irregular micro-villi.Surface area of the epithlial cell was larger.The junctions between lymphoiepithe-lial cells were tight, looked like cystal lattice.There Were few gohlet cells.Undertransmission electron microscop,the epithelial cells of CALT in chickens were composedof high electron density epithelial cells and low electron density epithelial cells.Thehigh electron density epithelial cells had a lot of microvilli,many cytoplasm processand vacuoles,irregular cell nucleus.Low electron density epithelial cells had fewmicrovilli and many microfold at the surface.There were a lot of microfilament incytoplasm,Cell nuclei were round or oval.Introepithelial lymphocytes could be seen.There were high-endothelial venules beneath basal lamina.Experiment of injecting HRP、Carbon、saccharomyces into artificially sealed conjunctival space indicated that CALTwas capable of antigen uptake and transport.All tracers were within the CALT, andmoved to deeper site as contact time increased.HRP were also in macrophages andlymphocytes.The results indicate that CALT is a component of the mucosal immunesvstem and site of antigen uptake,and plays an important role in paraocular immunityin chickens.